1. Field of the Invention
The present invention relates to a microgyroscope, and more particularly to a new high-performance, compact microgyroscope that can be easily reduced in size.
2. Description of the Related Art
Gyroscopes are inertial sensors that are widely used in airplanes, spacecrafts, and satellites and applications have spread to most industrial fields such as robots, automatic safeguarding equipment, remote controllers, and navigation assistants. Thus, there has been a demand for a lightweight, low power consumption, compact, and highly integrated gyroscope.
Gyroscopes that measure rotational movement of an object are divided into a mechanical type that uses an oscillator or the like and an optical type that uses laser or the like. Many studies have been made into optical gyroscopes since they can immediately start operation and exhibit a wide operating range. Optical gyroscopes mostly employ a ring interferometer scheme and a ring laser scheme. In the ring interferometer scheme, an optical fiber is wound into a ring and laser beams traveling in opposite directions in the optical fiber interfere with each other. Then, based on changes in the interference between the laser beams traveling in the opposite directions, a difference between lengths of paths through which the two laser beams travel as rotation occurs is measured to read the amount of the rotation.
FIG. 1 schematically illustrates a ring laser gyroscope. As shown in FIG. 1, in the ring laser scheme, a laser cavity is formed of a closed circuit and the interference between laser beams oscillated in both directions along the closed circuit is then measured. The laser beams are oscillated in opposite directions at different frequencies when rotation occurs and the difference between the frequencies is proportional to the amount of the rotation. Accordingly, the ring laser scheme exhibits high performance since the amount of rotation is measured by measuring the difference between the frequencies of laser beams based on interference between the laser beams.
However, application of optical gyroscopes is restricted since they are generally large in volume and also expensive.